One Linux command per day: Whereis command

The Whereis command can only be used for program name searches, and only binary files (parameter-B), man description file (parameter-m), and source code file (parameter-s) are searched. If the argument is omitted, all information is returned.

Whereis looks very fast compared to find, because the Linux system records all the files in the system in a single database file, and when you use Whereis and the locate described below, the data is looked up from the database, not like the Find command, By traversing the hard drive to find, the efficiency will naturally be very high.

However, the database file is not updated in real time and is updated once a week by default, so when we use Whereis and locate to find files, we sometimes find data that has been deleted, or just created the file, but cannot find it because the database file is not updated.

1. command format:

Whereis [-BMSU] [BMS directory name-f] File name

2. Command function:

The Whereis command locates the location of the executable file, the source code file, and the Help file in the file system. The properties of these files should belong to the original code, binary files, or Help files. The Whereis program also has the ability to search for source code, specify alternate search paths, and search for unusual items.

3. Command parameters:

-B locates the executable file.

-M locate the help file.

-S Locate the source code file.

-U searches the default path for files other than executables, source code files, and Help files.

-b Specifies the path to the search executable file.

-m specifies the path to the search Help file.

-s Specifies the path of the search source code file.

4. usage Examples:

Example 1: Find files related to * * files

Command:

Whereis SVN

Output:

[[email protected] ~] # Whereis Tomcat

Tomcat:

[Root@localhost ~] # Whereis SVN

SVN:/usr/bin/svn/usr/local/svn/usr/share/man/man1/svn.1.gz

Description

Tomcat is not installed, can not find out, SVN installation found a lot of related files

Example 2: only binary files are found

Command:

Whereis-b SVN

Output:

[[email protected] ~] # Whereis-b SVN

svn:/usr/bin/svn/usr/local/ SVN

[Root@localhost ~] # whereis-m SVN

svn:/usr/share/man/man1/svn.1 . GZ

[Root@localhost ~] # whereis-s SVN

Svn:

[Root@localhost ~] #

Description

whereis-m SVN Locate the description document path, whereis-s SVN Find source file .

This article is from the Linux Security Advisor blog, so be sure to keep this source http://chengyangyang.blog.51cto.com/9473151/1680896

One Linux command per day: Whereis command